1. Field of the Invention
This invention relates to a method and an apparatus for extracting portions of video data pieces to generate data representing digests of original pictures.
2. Description of the Related Art
Japanese patent application publication number 2005-252372 discloses a method and an apparatus for generating data representing a digest of original pictures. In the method and the apparatus of Japanese application 2005-252372, source video data is periodically sampled at prescribed time intervals to derive successive frames. The derived successive frames are analyzed to detect the moments of the start of every cutting, telop, and camerawork as special-technique starting points. The source video data is divided into portions, the boundaries between which coincide with the special-technique starting points respectively. Frames represented by each source video data portion are thinned out or decimated so that the source video data portion will be shortened to a digest video data piece. The rate of the thinning-out or decimating rises as the time length of the source video data portion increases. The resultant digest video data pieces are connected to form data (digest video data) representing a digest of pictures indicated by the source video data.
In the method and the apparatus of Japanese application 2005-252372, the sampling of the source video data to derive the successive frames and the analysis of the derived successive frames to detect the special-technique starting points tend to require a great amount of data processing. Therefore, it usually takes a long time to generate the digest video data.